Fixes the default stroke alpha to 1 if it's null.
Fixes the default stroke alpha to 1 if it's null.

Gama11/openfl,openfl/openfl,openfl/openfl,Gama11/openfl,Gama11/openfl,NenadBojkovski/openfl,openfl/openfl,Gama11/openfl,NenadBojkovski/openfl